The present invention relates to a manually guided or portable implement, especially a power chain saw, a brush cutter, a trimmer, or the like.
To operate a tool, such manually guided implements have an internal combustion engine, the cylinder of which is at least partially surrounded by an engine housing. In the region of the cylinder, the engine housing serves for the guidance of a cooling air stream that passes by the cylinder. The heat of combustion that is produced in the cylinder is absorbed by the cooling air stream, thus heating the latter.
To form a fuel/air mixture for operating the internal combustion engine, combustion air is drawn in that should have as great a density as possible for achieving a high engine output. For a correspondingly high air density, a temperature of the intake air that is as low as possible is desired. In this connection, the engine housing also serves to separate the cool atmospheric air from the heated-up cooling air stream in the intake region in order to avoid an undesirable heating and hence an accompanying loss of density in the intake air stream.
For maintenance work, especially at the location of use, it is necessary to have good access to the spark plug that is threaded into the cylinder. The spark plug, together with a spark plug connector arrangement that is placed on the spark plug for supplying it with an ignition voltage, extends through an opening in a wall of the engine housing for the spark plug. The spark plug connector arrangement can be pulled off from the outside, thus providing access to the spark plug for inspecting or replacing it. During removal of the spark plug connector arrangement, parts of the surrounding engine housing, and in particular the wall having the opening for the spark plug, can interfere and be in the way. It is difficult to remove the spark plug connector arrangement manually without a tool. For good electrical high voltage insulation, the outside of a spark plug connector is surrounded by a soft, elastomeric material that can be easily damaged when a tool is applied for lifting the spark plug connector arrangement off.
At the same time, it is desired to have as small a configuration of the opening for the spark plug as possible in order to limit the amount of heated-up cooling air that escapes. The small configuration of the opening for the spark plug, and the surrounding wall or housing components, limit the accessibility of the spark plug connector arrangement.
It is therefore an object of the present application to improve a manually guided implement in such a way that it is more maintenance friendly.